In a typical network, there may be multiple paths between two nodes, and the traffic flows between the two nodes may be bi-directional flows. For example, with equal-cost multi-path (ECMP) routing between two routers, each router can independently select the route or flow for each direction. Each router needs to have the smarts to appropriately select the route or flow when forwarding the traffic to the other router. This may result in asymmetric routing, which is a situation where packets follow a different route in an outbound direction than they follow when returning in the inbound direction. Requiring routers to have the smarts to select the route or flow may result in scaling issues, particularly for large routers, such as provider edge routers.
The subject matter claimed in the present disclosure is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area where some embodiments described in the present disclosure may be practiced.